# OpenTelemetry Collector for Metrics
# Deployment mode with Target Allocator (consistent-hashing)
apiVersion: opentelemetry.io/v1beta1
kind: OpenTelemetryCollector
metadata:
  name: otel-metrics
  namespace: opentelemetry
spec:
  mode: statefulset
  replicas: 2
  image: otel/opentelemetry-collector-contrib:0.113.0
  serviceAccount: otel-collector

  # Target Allocator - distributes scrape targets across collector replicas
  targetAllocator:
    enabled: true
    serviceAccount: otel-collector-targetallocator
    image: ghcr.io/open-telemetry/opentelemetry-operator/target-allocator:0.113.0
    allocationStrategy: consistent-hashing
    filterStrategy: relabel-config
    prometheusCR:
      enabled: true
      serviceMonitorSelector: {}
      podMonitorSelector: {}
      scrapeInterval: 30s
    resources:
      requests:
        cpu: 10m
        memory: 64Mi
      limits:
        memory: 128Mi

  resources:
    requests:
      cpu: 50m
      memory: 512Mi
    limits:
      memory: 1Gi

  ports:
    - name: otlp-grpc
      port: 4317
      protocol: TCP
      targetPort: 4317
    - name: otlp-http
      port: 4318
      protocol: TCP
      targetPort: 4318
    - name: metrics
      port: 8888
      protocol: TCP
      targetPort: 8888

  env:
    - name: K8S_NODE_NAME
      valueFrom:
        fieldRef:
          fieldPath: spec.nodeName
    - name: K8S_POD_NAME
      valueFrom:
        fieldRef:
          fieldPath: metadata.name
    - name: K8S_POD_IP
      valueFrom:
        fieldRef:
          fieldPath: status.podIP

  config:
    receivers:
      otlp:
        protocols:
          grpc:
            endpoint: 0.0.0.0:4317
          http:
            endpoint: 0.0.0.0:4318

      # Prometheus receiver with Target Allocator
      prometheus:
        config:
          global:
            scrape_interval: 60s
          scrape_configs:
            - job_name: otel-metrics-self
              scrape_interval: 60s
              static_configs:
                - targets: ['${env:K8S_POD_IP}:8888']
        target_allocator:
          endpoint: http://otel-metrics-targetallocator:80
          interval: 30s
          collector_id: ${env:K8S_POD_NAME}

    processors:
      batch:
        timeout: 10s
        send_batch_size: 1024
        send_batch_max_size: 2048

      memory_limiter:
        check_interval: 5s
        limit_mib: 400
        spike_limit_mib: 100

      k8sattributes:
        extract:
          metadata:
            - k8s.namespace.name
            - k8s.deployment.name
            - k8s.pod.name
            - k8s.node.name
        passthrough: false
        pod_association:
          - sources:
              - from: resource_attribute
                name: k8s.pod.ip
          - sources:
              - from: resource_attribute
                name: k8s.pod.uid
          - sources:
              - from: connection

      resourcedetection:
        detectors: [env, system]
        timeout: 5s
        override: false

    exporters:
      prometheusremotewrite:
        endpoint: http://prometheus-kube-prometheus-prometheus.prometheus.svc:9090/api/v1/write
        tls:
          insecure: true
        external_labels:
          otel_collector: ${env:K8S_POD_NAME}

      debug:
        verbosity: basic

    extensions:
      health_check:
        endpoint: 0.0.0.0:13133

    service:
      extensions: [health_check]
      pipelines:
        metrics:
          receivers: [otlp, prometheus]
          processors: [memory_limiter, k8sattributes, resourcedetection, batch]
          exporters: [prometheusremotewrite]